DESCRIPTION (Adapted from the Applicant's Description): The goal of this Mentored Research Scientist Development Award is to allow the candidate to develop basic research skills necessary for an independent career investigating movement impairments and the effects of rehabilitation. The long term goal of the proposed research is to better understand the mechanism by which cerebellar damage alters the production of normal movement and test whether rehabilitation strategies based on this knowledge can improve motor function. Studies have been designed to test the general hypothesis that a critical function of the cerebellum is to adjust the motor output controlling a given joint for the mechanical effects that other linked joints have on it. Experiments will address: (1) whether a general mechanism underlying limb ataxia is an inability to exploit/counter the "interaction" torques that are generated at a given joint by movement of another joint to which it is mechanically linked, (2) whether this type of dynamic correction, learned through trial-and-error practice, is impaired in subjects with cerebellar damage, (3) what factors contribute to abnormal joint movements observed in cerebellar gait ataxia, (4) how subjects with cerebellar damage adjust the locomotor pattern to varying environmental demands, and (5) whether rehabilitation strategies aimed at reducing the degrees of freedom (number of joints) to be controlled improve the reaching movements and gait of people with cerebellar damage. To address these aims, kinematic, kinetic, and electromyographic data will be collected from people with cerebellar damage and control subjects as they perform a variety of movements used in everyday function (e.g., walking on ramps , reaching with different loads). The proposed experiments are therefore designed to more clearly define the nature of impairments caused by cerebellar damage and test whether interventions based on these findings can improve the functional limitations of people with cerebellar damage.